Full-color LED-based lighting device

Abstract

A LED full-color lighting device contains a control unit, a light source unit, and a light display unit. The control unit relies on at least a potentiometer to apply various voltages to constant current sources, which in turn individually vary the current conducting through the red, green and blue LEDs of the light source unit, so as to deliver light of various colors. The colored light emitted from the light source unit can be easily and conveniently adjusted to fit a user's specific preference and mood. Colored patterns or textures can be formed on the light display unit so that the color of the light of the light source unit would mix with the colors of the patterns or textures to produce a visual effect as if some of the patterns or textures are changed.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention generally relates to lighting devices, and more particularly to a lighting device providing individual adjustment of the brightness of red, green, and blue light emitting diodes (LEDs) for full-color illuminating and presentation effects on the lamp shade or screen by controlling the amount of current flowing through the LEDs.[0003]2. The Prior Arts[0004]Currently, most of the LED-based color lamps available in the market provide various colored light by individually turning on and off the red, green, and blue LEDs of the lamp. For example, a control circuit of the lamp provides a 3-bit digital signal with each bit controlling whether to turn on (1) or off (0) the red, green, and blue LEDs, respectively. The lamp is therefore able to generate light of seven different colors, including red (001), green (010), blue (100), red plus green (011), green plus blue (110), blue plus red (101), and red plus ...

AI Technical Summary

Benefits of technology

"The present invention is a LED-based lighting device that can adjust the brightness of LEDs from complete darkness to full illumination, resulting in a theoretically unlimited number of colors. The device does not rely on human visual persistence to compensate for flashes of LEDs, delivering highly stable and comfortable lighting regardless of the color and brightness. The device is low-cost, easy-to-operate, and can be used for various purposes such as adjusting room lighting condition, creating a soothing, relaxing, or even exotic atmosphere. The device contains a light source unit with red, green, and blue LEDs, a control unit using potentiometers to adjust the brightness of the LEDs, and a light display unit that can be made of materials of appropriate transparency or colored patterns and textures to deliver different visual effects."

Problems solved by technology

However, adjusting the brightness of LEDs by voltage is difficult due to the specific semiconductor characteristics of LEDs.

A lamp based on the PWM-based approach therefore can only provide stable lighting in the medium-to-high brightness range and delivers only a small number of color combinations.

This technique would suffer the same drawbacks of the previous one.

Therefore, when a large number of LEDs are used, complicated heat dissipation mechanism has to be designed and employed, causing significant cost increase and reducing the applicability of the LED-based lamps.

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